It's not racist to be concerned about immigration; it's just a topic that many racists obsess about. Scotland has benefited from immigration in the past; a large number of Irish families, including my dad's family, immigrated to Scotland in the past and became productive members of Scottish society (not so much in my dad's case, admittedly, and it gave rise to a fair bit of sectarian violence), providing labour that fueled an expansion of heavy industry. Later on, Indian and Pakistani immigrants came, filling up a post-war labour shortage and opening a huge number of small convenience shops and takeaways, expanding the rather limited culinary horizons of the native Scots and sending their children to university to become doctors, engineers and other valuable specialists.
Now, however, the nature of immigration has changed. Instead of relatively educated, hard-working people coming, getting jobs, raising families and integrating into society, we're getting asylum seekers and seasonal workers. The asylum seekers come from oppressive or war-torn shitholes that have often traumatised and brutalised them, they often remain on benefits, instead of integrating, they tend to form enclaves, holding onto cultural practices that are incompatible with native values (forced marriage, honor killings etc) and are vastly more likely to be convicted of a crime than the natives. Seasonal workers are better, and are particularly useful to agriculture where time-sensitive crops like strawberries require a large temporary workforce to harvest them, but much of their wages go back home with them instead of returning to the local economy.