Err... no. Only if the difference between your total bonus and the DC never climbs above 20. If its a skill you intend to invest in, the +2 bonus to say Open Locks or Spot will at a minimum give you about the same advantage throughout your career as typically DC's and skill bonuses track together. But, often it's even better than that in that many common skill checks have a fixed difficulty (say DC 15 or DC 20). So ultimately, the +2 bonus may go from the difference between succeeding 60% of the time and succeeding 50%, to failing only 5% of the time intead of 15% of the time (or only 1/3rd as often). Your point is only valid when you spend the feat to improve something that you don't intend to invest anything else in AND the skill is one where the challenges tend to scale with level. In that case though, you are dealing not with a limitation of the feat, but a limitation of a d20 system. The complaint you are making like comparing a 1st level wizards attack bonus to a 1st level fighters attack bonus, and then complaining that at 15th level the difference between the two is very much greater relative and absolutely. Sure, yes it is. It's a known limitation of the D20 system, but that is very much beside the point.