I completely disagree and I think your word of warning is a little alarmist.
For 99.9% of the people out there looking to put their website up on a managed host, the 'unlimited' offerings are more then enough.
Yes, I only get 99,999 SQL databases, which should be enough. I also get unlimited Bandwidth usage...sure, there is probably a limit somewhere, but I will never reach it. Yep...I only get 99,999 domains...!!
So I must disagree with you...they do exist. Its like splitting hairs. Sure, there is a limit (99,999 SQL Data Bases, 99,999 domains, etc), and as far as mentioned, 99.9% of the users out there, that is sufficient to be considered unlimited.
Anything beyond that, and someone is by that time owning their own IP address and their own servers and leasing bandwidth from a local wholesale BW provider.
MY word of warning is this....don't get a host provider that 'JUST MEETS YOUR NEEDS' get something that you can for sure grow into so that you are not limited later on.
And yes, Hostgater is very inexpensive... For the amount of money it cost me each month, I am getting a LOT of stuff. Also, I usually evaluate my host providers every 1 to 2 years. By that time, things have changed so much I can usually get an even better deal.