I'd like to see more reactive counterplay to stealth rather than preventative counterplay of pink wards. The latter feels unrewarding and is little consolation when you get punished without any of the former (same reason a lot of players dislike assassins, which Riot's working on). I think it's a pretty big sign that stealth feels bad when the most common play against a stealth champ is to never push up your lane.
Also the vision vs stealth interplay atm feels pretty binary, and it's lame that stealth champs get to keep forcing you to spend money on consumable counters (IMO).
The bigger problem I think is that not one of the current implementations of stealth really seems "right" to me. You can either have someone who's hard to monitor from a distance, but who gives a warning when very close (Eve), but this makes it feel like warding is useless. Shaco's the opposite, but because he has a gapcloser, he can ignore a lot of warding locations too. Vayne is short duration tactical stealth, which is interesting, but very frustrating for champs without AOE damage as she can become untargetable and reposition herself frequently. In a game that's being increasingly steered toward skillshots, I think such a stealth implementation is also unhealthy (and dropping a pink ward as a solution adds so little depth to those situations).