Yes, I understand this, but I really like to hear what's wrong with Steam, even subjective arguments. So far I only heard monopoly=bad, which is not argument itself. It's not sarcasm, I'm really curious. Steam works just fine for me and it's the best DRM I ever met.
Alright, this is even on-topic for once so here I go
People dislike Steam through Valve for historical arguments. Much like EA gets flak for historical arguments. I even cite them myself because I'm tired of people holding other publishers to bygones while insisting Valve are "based Gaben" perfect. I'd love for any and all historical points to be dropped, but there you go.
Historical arguments range from "Steam was absolutely terrible when it was launched so why can't we let competitors at least evolve to a similar state before slamming them" to "look how Valve butchered these games for their platforms, so why can't other distributors". People made a huge hoo-hah about EA pulling games from Steam to sell them on Origin, but nobody ever batted an eyelid about Valve games being (to this day) Steam exclusives. As a more recent example, nobody has really picked up on how Steam enabled DotA 2 to be a success because the F2P game is placed in everybody's Steam Libraries by default. As is Team Fortress 2. No non-Valve F2P game gets this privilege.
This is Valve's perogative, absolutely. But it's a factor that makes people uneasy.
Actual arguments around the platform:
1. Offline Mode has historically been terrible, and Valve only made efforts to fix it when Origin
launched with a fully-functioning offline mode. In beta. I was personally affected by this for most of my uni days.
2. It's getting to the point where sales-based culture could arguably be a bad impact on certain demographics of games publishers / developers. Sales in some form are great for the consumer. Permanent sales at set times of year mean that people aim to buy games around those sales for a pittance of what they're actually worth. This is problematic and in my opinion will have a correlation in how publishers design their DLC strategies for modern games.
3. The UI. Still absolutely all over the place. Origin's is nice apart from not having a darker colour palette and that god-awful bubble UI everywhere.
4. Steam Guard.
Still doesn't work right.
5. Mobile apps; Android went un-updated for two or more years, only getting updates to force Steam Guard / 2-factor auth through the app that you
had to enable to use it. 2FA is a good principle, but should never be forced because tying everything to a single mobile phone is ironically Bad for when you inevitably lose your phone because:
6. Steam Support is still terrible. It's a wasteland.
7. Arbitrarily locking functionality behind Steam Account "levels" (that resulted in some people having their Friends List cut at the time) to push their XP-related Steam Sales minigames.
There are probably more but these are arguably the least-subjective issues people have had, and do have, with the platform.