Are good project planners as difficult to come across as it seems? Construction industry

Every contractor I work with, no matter how renowned and established their company, has a poor project planner. They take the schedules from their subcontractors, stick them together, and send that to us. Then request for a re-baseline when the end date shows as slipped. No critical thought applied whatsoever. Gaps between activities that won't realistically happen on the field, wrong logical linkage, etc.

We, client, end up pointing out all these aspects to them and it is a massive struggle getting a decent schedule, let alone on time. We are just lucky that we have good planners on our side - but their effort should not be higher than that of contractors contractually obliged to deliver on time, correct?

Ideally the contractors would look at maintaining the dates by optimising the resources they have, and should that not be enough, we can discuss the options together: increase resources and make me pay for it (if it's me who delayed you), re-baseline, etc.

I sometimes wonder if it comes down to competency, or if it's a strategy to gain some float in.. it's painful either way.