I agree that jungle starts can be slow, but I don't think they are as bad as people think
- Jungle starts are much easier with progress. It's all about getting calendar and getting to work, and hopefully getting springtime.
- Conversely, if you wanna play tradition then consider rerolling a jungle start. I know some people don't reroll, but you can still go progress in that case. Expecting to choose your pre-planned policy trees on no-reroll or other ironmanish modes is unrealistic.
- Having the chop at calendar restricts early teching, but I find this pretty reasonable. Getting calendar is not exactly expensive, and you're gonna be getting it soon anyway. Didn't chopping jungles used to require iron working? Now that was restrictive!
- In terms of terrain bonuses... I find the bonuses near your own capital are usually irrelevant, especially since you can quickly road it up if you end up fighting there