I am going to put in my 2 cents.
First of all, how does one explain 2.0 still beading/sheeting on many cars after several years?
1 - either it was not prepped/applied properly
2 - not maintained well, neglected, which is definitely at least one of the criteria, according to the OP.
The sandpaper like feel is a very good indicator that the car was not maintained properly. And that is the ONE requirement. So try a decon system like the Value guard ABC system or some other harsh cleaner.
And please don't take this the wrong way and I don't know who you are, heck, you maybe better than me at applying coatings, but it isn't as easy as slapping on some wax or sealant. We don't know any of the details about your prep work, or how you applied OC 2.0. Maybe you removed too much of it when wiping it.
PS: the guy who thought that 2.0 was discontinued due to not lasting? You couldn't be further from the truth.
OP - good luck and next time if 2.0 is gone from your car, try having a pro do the work. See if there is a difference in durability. Either way, you MUST wash the car regularly. You can't neglect it and blame the product.