Can't say I agree with that. With the squad Madrid have they should be walking the league, not finishing third. I don't think winning it should be considered exceptional, rather it should be standard. Barcelona have been poor this season, they've been there for the taking. Atletico are doing fantastically well, no doubt, but will they be up there again next season? Or will it be back to the status quo of Barca v Madrid.
In the PL you've got Liverpool 'doing an Atletico', Chelsea managed by Mourino, a strong City team, a perennial Arsenal and tough opponents in Everton, Southampton and, sometimes, Tottenham. Winning the PL is much harder, purely due to the fact that you could drop points against any team. In La Liga Real and Barca have to really try hard not to win against the smaller teams. Between 3rd and 4th in La Liga there are 16 points; between 3rd and 5th there are 24 points. You compare that with the PL where there are 3 pts between 3rd and 4th and only 10 pts between 3rd and 5th. It's much more even and, thus, harder.
When they're playing at home I'd say you're right, but it's the same with every other top team in every other league... Away games to smaller (possibly relegation-threatened) teams are by no means easy.
Dropped points in La Liga this season:
Atlético
- 0-1 away to Espanyol (12th)
- 1-1 away to Villarreal (7th)
- 0-0 home v Barça (2nd)
- 1-1 home v Sevilla (5th)
- 0-2 away to Almería (17th)
- 0-3 away to Osasuna (19th)
- 2-2 home v Real Madrid (3rd)
- 0-2 away to Levante (10th)
Barça
- 0-0 away to Osasuna (19th)
- 0-1 away to Athletic (4th)
- 0-0 away to Atlético (1st)
- 1-1 away to Levante (10th)
- 2-3 home v Valencia (8th)
- 1-3 away to Real Sociedad (6th)
- 0-1 away to Valladolid (16th)
- 0-1 away to Granada (15th)
- 2-2 home v Getafe (18th)
Real Madrid
- 2-2 away to Villarreal (7th)
- 0-1 home v Atlético (1st)
- 1-2 away to Barça (2nd)
- 2-2 away to Osasuna (19th)
- 1-1 away to Athletic (4th)
- 2-2 away to Atlético (1st)
- 3-4 home v Barça (2nd)
- 1-2 away to Sevilla (5th)
- 2-2 home v Valencia (8th)
- 1-1 away to Valladolid (16th)
From these the only real anomaly would be Barça's 2-2 at home with Getafe and Atléti's defeat at Almería. Otherwise, a lot of recurring smaller teams that have taken points off of two or all three, so hardly a case of them "trying really hard to not win".
Osasuna at home: 1 win and 2 draws v the Top-3
Levante at home: 1 win and 1 draw v the Top-3 (their game v RM finished 3-2 courtesy of a 90+4' winner from Cristiano Ronaldo)
Valladolid at home: 1 win and 1 draw v the Top-3 (lost 2-0 v Atlético)
Granada at home: 1 win v the Top-3; and narrow losses to RM (1-0) and Atlético (2-1)
The other recurring ones are top-8 (Athletic, Sevilla, Villarreal, Valencia; weirdly not so much Real Sociedad this season barring 1 home win v Barça).