By the time your academy could be producing 10 beakers per turn, techs are expensive enough that the benefits from bulbing would be many dozens of times that.
Sorry, but no. Let's say the game lasts 400 turns, which is the assumed starting point for a Future Era start. Let's say you got your first GS on turn 100. So that's 300 turns during which an Academy produces beakers.
+4 for 300 turns is 1200 beakers. That's the cost of a late Renaissance/early Industrial tech, right there, and would buy a dozen Ancient/Classical techs. Okay, we might subtract half off that as Opportunity Cost for not placing a Trading Post on the worked tile, so the practical gain might be more like 600. It's still far more than the cost of the techs available at the time you gained the GS (talking about your FIRST GS here); late-game GSs would have less time to build up that research surplus and would gain more from bulbing, so there's obviously a break-even point somewhere in between.
Obviously by the time you're getting +10 a bulb can save a huge amount, but remember that the Academy that's now getting +10 was getting +8 before that, and +6 before that, for hundreds of turns. It all adds up.
To see what I mean, let's pretend your city got a University on turn 150, an Observatory on turn 200, a Public School on turn 300, and a Research Lab on turn 350 before the game ends on turn 400 with a spaceship launch. You'd only place an academy near a core city, so it's reasonable to assume it'd get the full set ASAP. That means, using the core game's numbers:
> 50 turns of +4 = 200
> 50 turns of +6 = 300
> 100 turns of +8 = 800
> 50 turns of +10 = 500
> 50 turns of +14 = 700
Total: 2500 beakers. T14 techs (first tier of the Modern Age) cost 2600. Again we might chop off a fraction to represent the lost gold/production/whatever on that tile, but the fraction is less than before, because research buildings in the core game scale faster than ANYTHING. (Markets and Banks boost 25-33%, while research buildings are a uniform +50% until you hit the +100% lab?) Okay, Observatories can't be built in every city either, which'd possibly knock 400 off the total, but still over 2000 gained. (Of course, if you had a city that DID get an Observatory, then obviously you'd build your Academy there, so it's reasonable to leave that amount in.)
So, let's say you get a GS on turn 100. You can:
1> Build an Academy, and over time get a number of bulbs equal to the cost of an endgame tech. (And it's not just about the raw number; you'd be getting all of those intermediate techs a little bit faster as well.)
2> Use him right away, to gain a tech that might only cost a couple hundred bulbs. (Sure, that might take you dozens of turns, but it's still only a couple hundred. On the other hand, it'd give you the intermediate techs even faster than #1, some of which would improve your growth/research, so it has its merits.)
3> Stockpile him, paying maintenance along the way, to bulb an expensive late-game tech and/or one you REALLY need at a certain point, but get nothing until then.
Obviously, in my own mod (which is designed to have the game last 700-800 turns instead of 300-400) the break-even point is very different. But the core game's math still works in this way; option #1 is often the smart choice already, even if it's not the attractive game-changing choice we often want.
And again, we're talking about mods here, so you can make that option even better with minimal effort. Like I said, if the Academy gained an additional +2 research at some mid-era tech, wouldn't that shift the balance of whether the Academy is worth building? So if you don't like bulbing, my point was that, through mods, you can make bulbing the WRONG choice relative to making an Academy, without actually having to alter the bulb mechanism itself.