As Deus already mentioned, some argue pitchers aren't baseball players, and goalies aren't hockey players. A lot of sports have a weird position, but that doesn't mean they're not valuable players.
It's especially weird to hear this from a former football coach because football is especially ridiculous in terms of specialization. It's rare to see a 195 lb guy on the DL, just as you don't see a 300+ lb guy at cornerback (unless it's Wilfork).
And even that doesn't cover all the specialization. Some big guys play in a 3-4 but not a 4-3, some can play certain techniques in a 4-3 but not others, some corners are good in zone but not man, or man but not bump and run. Some QBs work well in one system but not another, some LBs will rush but can't cover, while others it's the opposite.
And yes, there's a guy who specializes in kicking. It's important enough to justify it's own roster spot and a full-time person practicing it. Kickers often lead their team in scoring, and it isn't just because of the extra points. Consider that Marshawn Lynch led the league in scoring among non-kickers last season. Ghost had more points via FG than Lynch.
And kickers have worked to improve significantly over the years. In 1967, 51% of FGs were made. Nowadays, that figure is over 80%, even after the worst week in kicking. Range has also increased. The percent of kicks made from 50+ yards has gone up each decade, from 13% in the 60s to 36% in the 80s to 53% in the 2000s up to 56% this year, which also is on pace to set the most attempts from 50+ record.
There may not be exactly the physical training that goes into some positions, but the mental training is incredible. The situations they face are some of the most stressful in the game.
Can't imagine Matt Stover is feeling a lot of love towards his old coach today...
